Manufacturing Technology Today

S. P. Lathkar ¹, B. Rajiv ², B. B. Ahuja ², S. K. Basu ²

Affiliations
1 MGM’S Research Centre, Nanded, IN
2 Department of Production Engineering and Industrial Management, College of Engineering, Pune, IN

Abstract

This paper presents comparative experimental study on machining characteristics of through holes (1000 micron) produced on special alloy steel, Stavax, thick plate with different types of dielectrics. Fast hole rotary Near Dry EDM (NDEDM) machine using tubular hollow brass electrodes are used for machining. Several holes are drilled using identical input parameters based on full factorial design of experiment procedure with four center points. Corresponding values of Material Removal Rate (MRR), Tool Wear Rate (TWR), MRR /TWR ratio & % Electrode Ratio are calculated and compared. The empirical relationship for above responses are developed using Regression Analysis. Surface Response Curves are plotted to compare response of interest. The results revealed that MRR,TWR & MRR/TWR (λ) ratio depends up on appropriate selection of input parameters as well as selection of dielectric.

Keywords

Near Dry Electro Discharge Machining (NDEDM), MRR, TWR, Surface Response Curves.

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J. K. Bagwan ¹, M. N. Shaikh ¹, B. Rajiv ¹, B. B. Ahuja ¹

Affiliations
1 Dept of Production Engg & Industrial Management, College of Engineering, Pune, IN

Abstract

The present experimental investigations are to evaluate the machinability of cryogenically treated AISI M2 HSS with copper as Tool in EDM process. The Experiments are performed to study the effects of input parameters such as Discharge current, Pulse on time, Duty cycle and Gap voltage on MRR, TWR and Radial overcut. Nowadays use of cryogenic treatment in machining is increasing day-by-day because the properties necessary for Tool we get after cryogenic treatment, except impact strength. After Cryogenic treatment there is improvement in the properties of the material such as electrical properties, thermal properties, brittleness and hardness. In this present investigation deep cryogenic treatment was done at -185°C for 36 hours on work piece (AISI M2 HSS) without tempering. Compared to conventional tool and work piece, the cryogenically treated work piece shows average increase 3.56% in MRR, the TWR is about 12.76%. The Radial overcut for cryogenic treated work piece is more than conventional EDM. The SEM images shows that machined surface of conventional EDM surface is better than cryogenically treated work piece.

Keywords

EDM, Deep Cryogenic Treatment, MRR, TWR, RSM.

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